Race and cause specific survival with prostate cancer: influence of clinical stage, Gleason score, age and treatment.

PURPOSE: We assess the influence of race on stage stratified cause specific survival of men with prostate cancer, and Gleason score, age at diagnosis and treatment on potential racial differences in survival.
MATERIALS AND METHODS: A total of 524 black and 396 white men were diagnosed with prostate cancer at a Veterans Affairs Medical Center between January 1982 and December 1992. Clinical stage was determined by retrospective review of the medical records and Gleason score of biopsy material as assigned by a single uropathologist. Of 611 patients who died the cause of death was determined by retrospective or prospective review of hospital records in 493 and by review of the death certificates in 102. In 16 cases the cause of death was indeterminate. Median potential followup was 112 months (range 60 to 182) and median period of observation was 61 months (range 1 to 182).
RESULTS: Cause specific survival with stage T1b-2 cancer was lower in 231 black than in 264 white men of all ages (p = 0.02) and lower in 110 black than in 170 white men younger than in 70 years at diagnosis (p = 0.04). Gleason 7 to 10 cancer, which was associated with a less favorable cause specific survival compared to Gleason 2 to 6 cancer (p <0.0001), was more common in black than in white men with stage T1b-2 cancer of all ages (p = 0.01) and younger than 70 years at diagnosis (p = 0.04). No or unknown treatment status, which was associated with a less favorable cause specific survival compared to treatment (p = 0.05), was more common in black than in white men with stage T1b-2 cancer of all ages (p = 0.0005) but not significantly different when stratified by age. In men of all ages racial differences in cause specific survival were not significant when adjusted for age and Gleason score (p = 0.14) or age, Gleason score and treatment status (p = 0.17). In men younger than 70 years racial differences in cause specific survival were not significant when adjusted for age and Gleason score (p = 0.22). There were no significant racial differences in overall or age stratified all cause survival of men with stage T1b-2 cancer. There were no significant differences in overall or age stratified cause specific or all cause survival of 112 black and 58 white men with stage T3-4 cancer, or 181 and 74, respectively, with metastatic cancer.
CONCLUSIONS: Our data indicate that local stage prostate cancer is more lethal in black than in white men and the difference is most pronounced in men younger than 70 years. The survival disadvantage of black men with local stage cancer is due in part to a propensity for development of less differentiated and more aggressive malignancies.